The invention relates to an apparatus and method for separating liquids.
It is generally recognized that there is often a need to separate, from each other, liquids which have significantly different properties, but which have become physically intermixed. This need arises, for example, with respect to various environmental problems. Hazardous liquids, such as oil, frequently become mixed with water found in the same environment. This then requires the separation of the oil from the water so that its presence may be eliminated as a hazard to the environment.
A wide variety of methods and apparatus have heretofore been proposed to provide an efficient means for removing oil or other liquid contaminants from water, but have met with little success. Recent methods of dealing with the problem of oil pollution include chemical dispersant, as well as various other methods for separating the oil from the water. For instance, U.S. Pat. No. 4,108,773, of Macaluso issued Aug. 22, 1978, teaches an oil salvaging apparatus comprising a chamber into the base of which oil-contaminated seawater is charged for separation of the liquids based on their different densities. However, the Macaluso technique, like many others, suffers from significant shortcomings.
Thus, in Macaluso, water is removed from the chamber in which separation is intended to take place by means of a pump. The outflow velocity of the water, therefore, will exceed the buoyancy force of the oil initially in mixture with the water. This counteracts the oil's ascent to the top of the chamber and instead, causes at least some of the oil to be discharged along with the water. Further, the Macaluso patent discloses no means for effectively regulating the contaminated water's injection rate, and the chamber will only support a predetermined weight of water under vacuum. Therefore, the injection rate may become excessive and this will result in the discharge of unseparated oil and water, either through the chamber's top oil evacuation conduit or out of its lower submerged end.
In general, the prior art techniques of separating liquids fail to take advantage of related fundamental fluid dynamics and separation principles and, therefore, are unable to achieve superior separation rates which are both measurable and predictable. Furthermore, prior art separation techniques are often incapable of assuring qualitatively acceptable end-products.
Other methods involve the use of skimmers, surface guides and the like to channel the surface oil to a location where it can be removed by pumps. However, in such methods, some water is usually removed with the oil.
In many cases, the oil is present in a thin layer, making it particularly difficult to remove without also removing water. Indeed, in such cases, large amounts of water must be processed, in order to separate relatively small quantities of oil.
Accordingly, it is an object of the present invention to provide an apparatus and method for overcoming some of the shortcomings of prior art liquid separation techniques.
It is another object to provide an apparatus and method to accomplish separation of different liquids in an improved manner.
It is still another object to accomplish such separation at controlled rates.
It is still another object to accomplish such separation with greater efficiency and reliability.
These and other objects which will appear are achieved in accordance with the present invention as follows.